The expanded OCC was a world-class facility built to accommodate the complete Sydney Metro, with controllers constantly monitoring the entire System, controlling the trains, tunnels, platforms, and sky train 24hrs, 7 days a week. The expansion of the OCC then incorporated the second stage of the Sydney Metro – Sydney Metro City & Southwest. Stage one of the Sydney metro line, the Metro North West, which opened in May 2019, was already managed and controlled through the OCC.